With news that Toyota and Alfa Romeo are about to enter the fray, we thought we'd list five favourite four-cylinder roadsters.

MAZDA MX5

After 24 years nothing has come close to the wee MX5, which still charms the socks off all who drive it. Labelled a hairdresser's car only by those who haven't driven it. Rag and solid droptops from $51,100.

BMW Z4

After the disastrously dull Z3, the later Z4 at last showed BMW's promise, with the company's latest four-cylinder versions proving better than its sixes if you want balance and poise. Expensive at $108,900.

MINI COOPER S

The roadster two-seater version of the Cooper S is easily the most fun version of what is already a fun car. No rear seats, but plenty of load space, means it's practical, to a point. Priced from $55,800 to $67,200.

MERCEDES-BENZ SLK

The smallest 200-series four cylinder model is the most poised in the range in the face of some storming V6s and V8s, but at less than $88,900 it's something of a secret bargain. So rare we can't get a tester.

VOLKSWAGEN GOLF CABRIOLET

It's a four-seater, so it's not really a roadster, but you can't ignore any car that offers as much powered top-down fun, for only $43,500 - the cheapest here. VW also has the Eos and that's not a proper roadster, either.